Hard to start big bore 63mm 185psi By jahno45 (Read 323 times)

[jahno45]

Hey guys,

I installed a big bore 63mm cylinder to my SYM 150 and Ii gives the bike that extra torque it needed to pull hills and tow
without killing my gas tank.

my problem is the bike will only start if I rotate the engine past top dead center and than hit the starter. I tried going from
the 7amp battery to a 9amp battery with more cranking amps, but still got the same result.

Is there anything else I should be trying.

PS compression is now at 185psi

Thanks in advance David

[cyborg]

Not much to do except get a thicker head gasket to lower compression ratio,,, my Stella comes to rest with the same result as yours,,, I kick it thru the comp stroke and then hit the button,,, small price to pay for better performance in my book,,,it will settle down as the miles pile up also

[crwford]

I would recheck the rocker arms maybe even close gap a little more. I know ohv for mowers have this problem and that how we solved this problem.

[thecableguy]

What CDI are you using? Most of the "performance" ones advance the timing at idle, making the scoot hard to start, just like you are describing.

Try the variable timing performance CDI that John sells, it worked GREAT for the same problem I had!

variable-timing-performance-cdi-nycsp0007